Graphene nanosheets loaded Fe3O4 nanoparticles as a promising anode material for lithium ion batteries

A novel synthesis strategy has been developed to synthesize graphene nanosheets loaded Fe3O4 nanoparticles (GNSs/Fe3O4 NPs) via a freeze-drying of graphene and iron ion suspension and by a solvent thermal synthesis method sequentially. The size of Fe3O4 loaded on the graphene nanosheets can be regulated from 20 nm to 100 nm by controlling the mass ratio of GNSs and Fe3O4. When the ratio of GNSs to Fe3O4 is 1:2, the obtained Fe3O4 nanoparticles have similar to 40 nm in diameter. Lithium ion battery anode made from GNSs/Fe3O4(1:2) without adding any other conductive agent can exhibit a high reversible capacity (similar to 1145 mAh g(-1) after 120 cycles at 100 mA g(-1)) and a remarkable rate capability (650 and 530 mAh g(-1) at 0.5 and 1 A g(-1), respectively). This excellent performance is caused by the uniform dispersion of Fe3O4 nanoparticles on the graphene nanosheet surfaces, and thus achieving a large specific surface area and the structural integrity during the Li+ insertion/extraction process. (C) 2019 Elsevier B.V. All rights reserved.